Not Applicable.
Not applicable.
Not applicable.
1. Field of the Invention
The present invention is directed to a coupler for connecting two structural beams or piles. More particularly, the present invention is directed to a friction coupler for structural beams of the like and can be used to repair and rebuild structural beams having one or more damaged sections.
2. Description of the Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
Coupling two structural members together is often desirable. In some situations it is difficult or undesirable to weld or bolt the two members together. In other situations, there may be a damaged section in a single beam or member that must be repaired or replaced in order to reestablish the structural integrity and strength of the member. Since replacement of damaged piles is very expensive and since much of a damaged underwater pile typically remains sound (typically the length under the splash zone), many efforts to permit repair of piles have been made. Some of these have lead to issued patents.
U.S. Pat. No. 3,333,429, issued to Dougherty, on Aug. 1, 1967, discloses an xe2x80x9cH-beam Pilingxe2x80x9d comprising fastening sections of H-beams together with a welded butt joint. A butt weld does not provide the strength necessary in many applications and naturally assumes that the two end to be joined are sound. This is obviously not the case when a pile has been damaged. If a replacement section is used, it could not be properly loaded prior to the butt welding of Dougherty.
U.S. Pat. No. 3,720,068, issued to De Rosa on Mar. 13, 1973, discloses a xe2x80x9cMethod and Apparatus for Splicing Replacement Pile Section to a Pile Stubxe2x80x9d in which a bore is formed in the stub pile below the mud line and a vertically oriented drift pin is inserted into the bore. A concentric groove is cut into the pile stub and a matching bore and groove are cut into the end of the replacement pile section. A circular cross section sleeve is inserted into the groove in the stub pile and the replacement pile is placed on top of the stub pile. Suitable glue, such as epoxy is applied. Connector plates F are arranged to overlap the joint between the replacement pile section and the pile stub and are nailed into place with many nails (FIGS. 4, 61). A protective felt is wrapped around the joint and a rubber boot is placed over it. This system cannot work with steel H-piles and is only useful below the mud line since it has little shear strength and lateral support comes from the surrounding mud.
U.S. Pat. No. 3,890,795, issued to Maurer on Jun. 24, 1975, discloses a xe2x80x9cKit of Components and a Method of Protecting Steel Piling from Corrosionxe2x80x9d comprising a tough flexible plastic jacket that is snugly gathered and cinched about an H-beam type piling to prevent corrosion. Maurer ""795 does not and cannot be used to repair a damaged H-pile.
U.S. Pat. No. 3,934,422, issued to Fredrickson et al. on Jan. 27, 1976, discloses a xe2x80x9cPile Splicing Apparatus and Methodxe2x80x9d comprising building a reinforcing structure of reinforcing bar, concrete mesh reenforcement bar stock or the like, placing a concrete form bag about the reenforcement bar area, and filling the bag with concrete. If the splice is located below the mud line, the mud is excavated to a depth to allow the concrete to set up on bedrock or the like. This patent is enclosed for general reference. Fredrickson et al. ""422 requires a lot of space between adjacent piles to accommodate its bulky concrete form bag and requires excessive labor in that it is basically an underwater concrete form, complete with an extensive reenforcement bar network.
U.S. Pat. No. 4,610,571, issued to Lees on Sep. 9, 1986, discloses a xe2x80x9cFoundation system and Pile Coupling for Use Thereinxe2x80x9d comprising a circular cross section collar that is placed over the end of one pile section. The other pile section is inserted into the collar. Spring loaded pins in the collar are then inserted into horizontal holes that were pre-drilled in the ends of the two pile sections (see FIGS. 2-4.). Lees ""571 assumes two sound butt ends of two pile sections that are to be joined together. This collar system will not work when the sections are damaged. Lees does not provide substantial shear strength and does not work with the irregularly shaped piles, such as H-piles.
U.S. Pat. No. 5,337,469, issued to Richey on Aug. 16, 1994, discloses a xe2x80x9cMethod of Repairing Polesxe2x80x9d comprising removing the lowered damaged portion of a utility pole and replacing that section with a steel pole or stanchion. The top of the stanchion has a platform that the upper or remaining end of the utility pole rests on. A sleeve or split socket 52 is on the top of the stanchion. The socket is closed by adding any missing sections of the socket, which is then bolted together, surrounding a portion of the existing pile. The space between the socket and the pole is filled with urethane foam. The socket or sleeve includes roughly circular cross section sections, each having an outwardly extending flange, which each flange having a number of spaced apertures along its length. Flanges and bolt holes from adjoining flanges are bolted together (See, FIGS. 6, 7, and 8). This method cannot be used underwater without substantial modification and does not provide substantial shear strength. Further, it is designed for use with wooden poles and is not suitable for steel poles or H-piles. Moreover, the many steps required to utilize Richey ""469 would make it uneconomical in underwater use.
U.S. Pat. No. 5,573,354, issued to Koch on Nov. 12, 1996, discloses a xe2x80x9cTimber Pile Repair Systemxe2x80x9d comprising a two piece jacket, with each section having a semi-circular cross section, and a radially extending flange on each end, with apertures through the flanges. The flanges from two sections are aligned when the two sections are placed about a circular cross section pile and then are bolted together (See FIGS., 1-4). Any voids from deteriorated pile sections can be filled with epoxy. Koch ""345 cannot be used with H-piles. Further, the use of epoxy resins to file the voids in deteriorated pile sections is very expensive and labor intensive.
U.S. Pat. No. 5,813,800, issued to Doleshal on Sep. 29, 1998, discloses a xe2x80x9cProcess for Replacing and Loading a Damaged Section of a Pile.xe2x80x9d Doleshal ""800 shows a two-piece circular cross section coupler for wooden piles, with a flange at each end of the coupler sections, which are bolted together along the flanges. The coupler also includes spikes that are driven into the circular pile (FIGS. 15A and 15B). The patent also discloses a H-pile coupler comprising flat steel plates bolted to the flat sides of the H-pile. A replacement H-pile section is fastened to the flat steel plate reinforcement members. Doleshal ""800 can only be used in connection with an elaborate truss system used to support hydraulic rams that hold a two sections of H-pile apart and subject it to design loads while an entire replacement section of H-pile is inserted between the two pile ends. It is often desirable to repair a pile without the necessary expense used in this method and in a fashion that requires less working space.
In marine applications, pile is submerged underwater and the water typically damages the relatively small upper portion of the pile that is located in the splash zone, which usually extends from the highest level reached by the water""s waves to a level about six to ten meters below the normal surface level of the water due to the action of the waves, entrained abrasives, marine animals, and the high levels of dissolved oxygen at these levels. Thus, normally only a relatively short portion of a pile is subjected to excessive deterioration. Replacing the entire pile is considerably more work and expensive than repairing the damaged section.
Each of these above methods is specially designed for a special circumstance and each falls short in other circumstances or has shortcomings set out above. Moreover, each is very labor intensive and, when the application is underwater, is therefore very expensive and dangerous to utilize.
Therefore there is a need for a method and apparatus for repairing damaged pile, particularly an underwater pile, sections that requires minimal working space around the pile; that requires a minimal amount of labor, and, particularly, underwater labor; that restores damaged pile sections to original design strength in compression, shear, and tension; and that provides a permanent repair for the life of the pile.
Accordingly, it is a primary object of the present invention to provide an apparatus for repairing damaged pile sections, particularly an underwater pile, that requires minimal working space around the pile.
It is another object of the present invention to provide an apparatus for repairing damaged pile sections that requires a minimal amount of labor, and, particularly, underwater labor.
It is another object of the present invention to provide an apparatus for repairing damaged pile sections that restores the damaged pile section to its original design strength in compression, shear, and tension.
It is another object of the present invention provide an apparatus for repairing damaged pile sections that provides a permanent repair for the life of the pile.
The frictional coupler and stiffener 10 works by providing at least one sheathing member that runs from a sound upper portion of a pile to be repaired to a lower sound portion of a pile to be repaired and is firmly clamped to the upper sound portion of the pile and to the lower sound portion of the pile, thereby transferring the compressive load on the pile from the upper sound portion of the pile to the sound lower portion of the pile, bypassing the need for the damaged or deteriorated pile section to carry this compressive load. This type of structure and this principle of operation is employed in all embodiments of the frictional coupler and stiffener. In some applications, a single sheathing member can be fastened to the pile above and below the damaged or deteriorated section, with a clamping ring or plate bolted to the pile. In other applications, which are likely more common in practice, more than one sheathing member, or channel reinforcing member, is employed to provide symmetrical loading of the coupler. Clamping forces are provided by highly tightened bolts that pass through apertures in flanges of the sheathing members, which lie outside the pile, and are threaded with mating nuts. A spacer member or element is located adjacent to the outer edge of adjacent flanges farther from the pile than the bolt holes so that tightening the nuts and bolts squeezes and clamps the frictional coupler and stiffener rather than simply bending the flanges. The flanges, if they bend, pinch the sheathing members more tightly about the pile since their outer ends cannot move closer together due to the spacer member, which, for these purposes, is essentially incompressible at the forces used in this application.
A frictional coupler and stiffener (hereinafter xe2x80x9cfrictional couplerxe2x80x9d) for structural beams and piles according the present invention basically provides a patch or a bridge about a damaged pile section, which is clamped to the pile along the damaged pile section and is also clamped to a sound portion of the pile above and below the damaged section. The frictional coupler and stiffener is designed to be used wherever a pile needs reinforcement. This most likely will occur when the pile has been damaged, as for example by being hit by a ship, or deteriorated through exposure to the water and waterborne organisms. In some cases, however, it may desirable to utilize the frictional coupler and stiffener simply to strengthen a sound pile due to the desire to increase the load on the supported structure, such as a pier or dock, beyond the original design load.
In one embodiment adapted for an H-pile, a channel patch member comprising a basically U-shaped channel is fastened to each corresponding channel of the sound portions of the H-pile, contacting it above and below the damaged or deteriorated section of the H-pile by one or more bolts and nuts. A flange portion of each outer edge of each channel patch member extends beyond the corresponding edge of each H-pile channel and each flange includes a row of apertures. A locking bar includes a row of apertures that align with theapertures of the flanges of the channel patch members and includes a flange portion that is the same thickness as the material the H-pile is made from. The locking bar flange is perpendicular to the locking bar and extends throughout the length of the locking bar. Four separate locking bars are used-one for each channel patch flange portion and are placed on the outer surface of the H-pile flange portions. The locking bars are bolted to the flange portions of the channel patch members along the entire rows of aligned apertures. The resulting frictional coupler and stiffener provides a patch for a deteriorated or damaged section of an H-pile that is as strong as the original design specifications of the H-pile.
An embodiment adapted for repair of damaged cylindrical piles includes a plurality of metal sheets bent into an arcuate shape on the same radius as the cylindrical pile to be repaired, with a flange projecting outwardly from the vertical edges of each section. A plurality of aligned holes allows adjacent flanges to be bolted together. A flange spacer element at the outer edge of one flange prevents the outer edges of the flanges from being bent, thereby assuring that the compressive forces from tightening the bolts will be principally directed to squeezing the cylindrical pile itself.
Other objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, the preferred embodiment of the present invention and the best mode currently known to the inventor for carrying out his invention.